The bank told customers that two tapes disappeared in transit while being shipped to one of its location in March. The company has not been able to find the tapes. The tapes were unencrypted and contained extensive customer information, including Social Security numbers and bank account numbers, the bank told the office of Massachusetts Attorney General Martha Coakley.

TD Bank, one of the largest regional banks in the United States, had previously refused to say how many customers may have been affected by the error.